Construction
at Borobudur probably began around AD 760 and seems to have been
completed by about 830. Work on the reliefs was probably divided
among several groups of sculptors. The masters first sketched
the main outlines of the scenes, and their apprentices then did
most of the rough work. The masters returned in the final stages
to apply the finishing touches to the panels

The stones
we view today when we visit Borobudur were not meant to be seen
at all, for the entire monument was originally coated with white
plaster and then painted. The plasterwork would have required
skill, for very fine details were moulded using this medium.